One of the most common urological procedures, both historically and in current practice, is the placement of a catheter in the urethra for the purpose of draining urine or fluid, to diagnose problems or to maintain anatomic continuity. This procedure is performed by inserting the catheter manually while noting any resistance to forward movement as shown by a failure of the catheter to slide smoothly into the urethra. While most placements proceed without problems, typically about ten percent of urinary catheter placements are difficult, causing a substantial burden on the delivery of effective care through the healthcare system. The most common problem is tetany, a spasm of the external urinary sphincter or stricture of the urethra. Stones, and even clots descending from the bladder, also constitute urethral obstructions. In addition, urethral lumen calibers vary considerably, and particularly with urethritis, BPH, urethritis stricture disease and prostate disorders in males. The cost to the healthcare system, hospitals, clinics and doctors' offices is substantial. In addition, the delay in servicing urological catheter patients in a timely manner constitutes poor medical efficiency, delivery and control. When difficulty is encountered, the resulting frustration among healthcare professionals, especially nurses, physician extenders and physician assistants, creates a very real feeling of ineffectiveness on the part of these healthcare workers, to say nothing of the dissatisfaction on the part of the patients caused by the delay and added discomfort. While the dollar cost to the healthcare system is not the only concern, such elements as added labor and material costs, time delays for patient rectification, excess space and equipment required, catheter kit value, nurse technician and physician costs constitute an expense to the healthcare system of surprising proportions. The best available current data indicates about 150,000 urinary catheter placements are made in the United States per day. Of these, about 15,000 are difficult. From this data it can be calculated that the cost to the healthcare system for additional services by healthcare professionals in the United States is over $700 million dollars per year. Moreover, the additional space and equipment amounts to at least $800 million per year for a total added cost of about $1.5 billion per year.
Accordingly, an important object of the present invention is to virtually eliminate these additional costs, greatly improve patient comfort and satisfaction, as well as shortening the time required for catheter placement while adding only a relatively small cost to the equipment required.
Another more specific object of the invention is to eliminate or drastically reduce problems associated with difficult urethral catheter passage including the formation of iatrogenic trauma strictures, urethral bleeding, urethral mucosal lining tears, patient pain or discomfort, scar tissue formation, treatment delay, increased infection potential, and inappropriate use of antibiotic which may enhance a recalcitrant immune strain modification of the offending organism.
A further specific object of the invention is to provide an apparatus and method for safely passing a catheter through the urethra of both male and female human patients with a provision for enabling healthcare workers such as nurses and physician's assistants who are not board certified urologists to negotiate most obstructions in a safe, efficient and timely manner without the need of a cystoscope.
In several kinds of surgical operations, e.g., urological procedures, it is the current practice to insert and remove various instruments through the urethra several times during a single surgical operation. The repeated insertion and removal of instruments often requires a significant amount of force. This can of course traumatize the tissue. It is therefore another object of the present invention to eliminate the need for inserting and removing a series of surgical instruments by passing them through an opening in the body in a manner that can cause discomfort or injure the tissue and in that way reduce the possibility of bleeding, trauma, inflammation; infection, false passage, and long-term complications such as scarring.
In addition, the manipulation of a surgical instrument or other object that is partially or completely inserted into the body can also result in damage to the surrounding tissue. A more specific object of the invention is to minimize the possibility of damaging the tissue through either the manipulation or the repeated insertion and removal of instruments that have to be used in succession to complete a surgical operation: For example, in many urologic procedures a cystoscope is inserted blindly or under direct vision for evaluation and diagnosis. The cystoscope is frequently removed and another instrument then inserted for lavage, cauterization, extraction or surgery. A series of such instruments are usually inserted in a logical sequence. Finally, at the conclusion of the endoscopic or percutaneous procedure, it is frequently necessary to insert a catheter as a percutaneous drain or for drainage of the bladder or as a post-op drain. The insertion and removal of each of these other instruments increases the chances for traumatizing or injuring surrounding tissue or even creating a false passage and losing access. Moreover, each time a body orifice, i.e., oral cavity, urinary, gastrointestinal tract or other opening is manipulated, the potential for bacteremia is increased. In short, tissue trauma can result from retrograde or antegrade passage instrumentation or removal of foreign bodies. Moreover, many endoscopic, percutaneous or laparoscopic instruments have a relatively small diameter working channel which limits the size of biopsy specimens. The small size limits the removal of such specimens or foreign bodies by necessitating multiple insertions and withdrawals. This prolongs the operation and is an additional source of tissue trauma. Finally, when one instrument is removed and replaced by a second instrument, positioning the distal end of the second instrument is inexact because there is nothing present to locate the second instrument at a predetermined stop point with respect to the position taken by the previous instrument.
While it is known in the art to use a sheath to facilitate the insertion of a small catheter into the body, as described for example in U.S. Pat. Nos. 4,581,025 and RE31,855, no provision is made for accommodating a series of surgical instruments including endoscopes, cauteries, or instruments used in removing tissue for biopsy. Moreover, no provision is made for holding the patented sheath in place nor is there any provision for introducing anesthetic or medication. Accordingly, it is a more specific object of the invention to provide a method and surgical instrument that can be placed percutaneously or transurethrally for facilitating both endoscopic surgery or cystoscopic procedures so as to ease the successive placement, manipulation and removal of various surgical instruments including relatively bulky or rigid instruments such as endoscopes, cautery instruments, cold knife scalpel instrument, and biopsy instruments without increasing the likelihood of bleeding, trauma, inflammation and long-term complications. Another object of the invention is to provide such an instrument with a provision for holding itself securely in place during use while permitting introduction of fluids, e.g., for irrigating the tissue or for anesthesia, etc., and for accommodating instruments that are larger than the lumen of the working sheath. Yet another object of the invention is to provide a method for using such an instrument.
These and other more detailed and specific objects of the present invention will be better understood by reference to the following figures and detailed description which illustrate by way of example of but a few of the various forms of the invention within the scope of the appended claims.